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Shuttle-like copper oxide (CuO) was prepared by a hydrothermal decomposition process. The resulting material was characterized by scanning electron microscopy and X-ray diffraction. It was then immobilized on the surface of a glassy carbon electrode modified with a film of poly(thionine). A pair of well-defined and reversible redox peaks for Hg(II) was observed with the resulting electrode in pH 7.0 solutions. The anodic and cathodic peak potentials occurred at 0.260 V and 0.220 V (vs. Ag/AgCl), respectively. The modified electrode displayed excellent amperometric response to Hg(II), with a linear range from 40 nM to 5.0 mM and a detection limit of 8.5 nM at a signal-to-noise ratio of 3. The sensor exhibited high selectivity and reproducibility and was successfully applied to the determination of Hg(II) in water samples. 相似文献
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Zhiqiang Gao Mingxian Zi Yimin Zhang Guangqiang Wang Zaofan Zhao 《Mikrochimica acta》1993,111(1-3):63-70
The electrocatalysis of nitrite in solutions at an inorganic film modified glassy carbon electrode was studied. The modifier was an electrodeposited thin inorganic film of the copper-heptacyanonitrosylferrate (CuHNF). Cyclic voltammetry of the modified electrode in a nitrite solution revealed that both oxidation and reduction of nitrite were catalyzed and the electrocatalytic currents were controlled by the diffusion of nitrite. Voltammetric and amperometric responses were investigated. When applied as an amperometric sensor in a flow injection system, the modified electrode permitted detection at — 0.55 V, over 500 mV lower than at the naked electrode surface. A linear response range extending from 1 × 10–6 to 1 × 10–3
M nitrite was obtained, with a detection limit of 3 × 10–7
M. The relative standard deviation for 50 repetitive injections with a 5 × 10–5
M nitrite solution was less than 4%. The procedure was applied to the determination of nitrite in saliva and nitrate. 相似文献
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Zhou Zhiping Zhou Yueming Liang Xizhen Luo Jianqiang Liu Shujuan Ma Jianguo 《Journal of Solid State Electrochemistry》2022,26(5):1139-1149
Journal of Solid State Electrochemistry - Herein, a novel strategy for sensitive determination of uranium in natural water was proposed using electropolymerization of Nile blue modified glassy... 相似文献
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A sensitive and selective electrochemical sensor for the determination of nitrobenzene (NB) was developed based on a carbon paste electrode (CPE) modified with a nanocomposite prepared from the conducting polymer poly(3,4-ethylenedioxythiophene) and carbon nanotubes. The modified CPE exhibits good conductivity, a large surface area, and excellent catalytic activity towards the electrochemical reduction of NB. Under optimal conditions, the modified CPE is capable of detecting NB in the 0.25 to 43 μM concentration range and with a detection limit at 83 nM. Moreover, the sensor is highly stable and reusable, and free of interferences by other commonly present nitro compounds. It was used to determine NB in wastewater samples. Figure
A sensitive nitrobenzene sensor was developed based on the chemically synthesized nanocomposite composed of conducting polymer poly(3,4-ethylenedioxythiophene) and carbon nanotubes, which showed excellent catalytic activity towards the electrochemical reduction of nitrobenzene. 相似文献
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Electrochemical determination of dopamine using a poly(2-picolinic acid) modified glassy carbon electrode 总被引:8,自引:0,他引:8
A poly(2-picolinic acid) chemically modified electrode (CME) for the determination of dopamine (DA) by cyclic voltammetry is described. Compared with a bare glassy carbon electrode, the CME exhibits a 200 mV shift of the oxidation potential of DA in the cathodic direction and a marked enhancement of the current response. In pH 7.0 buffer solution, a linear calibration graph is obtained over the range from 2.5 x 10(-7) to 1.0 x 10(-5) mol dm-3 with a correlation coefficient of 0.998. The detection limit is 3.0 x 10(-8) mol dm-3. The modified electrode eliminated efficiently the interference from ascorbic acid (AA) when present in a 150-fold concentration ratio. It also showed excellent stability and reproducibility. 相似文献
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Antonio Radoi Simona-Carmen Litescu Sandra A. V. Eremia Mihaela Miu Mihai Danila Adrian Dinescu Gabriel-Lucian Radu 《Mikrochimica acta》2011,175(1-2):97-104
Multiwalled carbon nanotubes with nanosized sputtered gold were used to modify a glassy carbon electrode (GCE). The substrate was characterized by scanning electron microscopy (SEM), X-ray diffraction, cyclic voltammetry and amperometry. SEM micrographs indicated an uniform coverage of the carbon nanotubes with nanosized (poly)crystalline gold. Cyclic voltammetry reveals that peak separation of the unmodified GCE in the presence of 1?mM ferricyanide is 131?mV, but 60?mV only for the modified GCE. In addition, the oxidation of NADH (1?mmol?L?1 solution) begins at negative potentials (around ?100?mV vs. Ag/AgCl), and the anodic peak potential (corresponding to the irreversible oxidation of NADH) is found at +94?mV. The effect of pH on the electrocatalytic activity was studied in the range from 5.4 to 8.0. The relationship between the anodic peak potential and the pH indicated a variation of ?33.5?mV/pH which is in agreement with a two-electron and one-proton reaction mechanism. Amperometry, performed at either ?50 or +50?mV vs. an Ag/AgCl reference electrode, indicates that the modified electrode is a viable amperometric sensor for NADH. At a working potential of +50?mV, the response to NADH is linear in the concentration range from 1 to 100???mol?L?1, with an RSD of 6% (n?=?4). Figure
Multiwalled carbon nanotubes with nanosized sputtered gold were used to modify a glassy carbon electrode. The oxidation of NADH (1?mmol?L?1) begins at negative potentials (around ?100?mV vs. Ag/AgCl), and the anodic peak potential (corresponding to the irreversible oxidation of NADH) is found at +94?mV. 相似文献
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Herein, a poly(L-tryptophan) modified glassy carbon electrode (Ptry/GCE) for the determination of maltol is fabricated by electrochemical polymerisation. The electrochemical behaviour of maltol at the Ptry/GCE is studied by cyclic voltammetry (CV). The modified electrode shows excellent electrocatalytic activity towards the oxidation of maltol and the oxidation is a one-proton-one-electron process. In pH 8.0 phosphate buffer solution (PBS), the oxidation peak current of maltol shows a linear relationship with its concentration in the range from 9.00 × 10?5 to 3.75 × 10?3 mol L?1 with a correlation coefficient of 0.9972. The limit of detection is estimated to be 8.00 × 10?6 mol L?1. The novel method shows good selectivity, recovery, reproducibility and great convenience and has been satisfactorily demonstrated in real food sample analysis. 相似文献
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Microchimica Acta - The paper describes an electrochemical nitrite sensor based on the use of a nanocomposite consisting of poly(3,4-ethylenedioxythiophene) (PEDOT) doped with polyacenic... 相似文献
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Rao Hanbing Lu Zhiwei Ge Hongwei Liu Xin Chen Bingyao Zou Ping Wang Xianxiang He Hua Zeng Xianyin Wang Yanying 《Mikrochimica acta》2017,184(1):261-269
Microchimica Acta - The article describes an electrochemical creatinine sensor that is based on a glassy carbon electrode (GCE) modified with a magnetic molecularly imprinted polymer... 相似文献
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Hussain Mohammad Musarraf Rahman Mohammed M. Asiri Abdullah M. 《Mikrochimica acta》2016,183(12):3265-3273
Microchimica Acta - Strontium oxide nanorods (SrO NR) were prepared in alkaline medium by a wet-chemical method. They were characterized by FTIR, UV/Vis, field emission scanning electron... 相似文献
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Junhua Li Daizhi Kuang Yonglan Feng Fuxing Zhang Zhifeng Xu Mengqin Liu Deping Wang 《Mikrochimica acta》2013,180(1-2):49-58
We report on a glassy carbon electrode that was modified with a composite made from graphene oxide (GO) and multiwalled carbon nanotubes (MWCNT) that enables highly sensitive determination of L-tyrosine. The sensor was characterized by transmission electron microscopy and electrochemical impedance spectroscopy, and its electrochemical properties by cyclic voltammetry, chronocoulometry and differential pulse voltammetry. The GO/MWCNT hybrid exhibits strong catalytic activity toward the oxidation of L-tyrosine, with a well defined oxidation peak at 761 mV. The respective current serves as the analytical information and is proportional to the L-tyrosine concentration in two ranges of different slope (0.05 to 1.0 μM and 1.0 to 650.0 μM), with limits of detection and quantification as low as 4.4 nM and 14.7 nM, respectively. The method was successfully applied to the analysis of L-tyrosine in human body fluids. The excellent reproducibility, stability, sensitivity and selectivity are believed to be due to the combination of the electrocatalytic properties of both GO and MWCNT. They are making this hybrid electrode a potentially useful electrochemical sensing platform for bioanalysis. Figure
A new L-tyrosine electrochemical sensor was fabricated based on graphene oxide and multiwalled carbon nanotube. The prepared sensor exhibits excellent electro-catalysis to the oxidation of L-tyrosine, and can improve determination sensitivity and decrease detection limit. This sensor was successfully applied to detect L-tyrosine in human fluids with satisfactory results. 相似文献
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This report described the direct voltammetric detection of peroxynitrite (ONOO−) at a novel cyanocobalamin modified glassy carbon electrode prepared by electropolymeriation method. The electrochemical behaviors of peroxynitrite at the modified electrode were studied by cyclic voltammetry. The results showed that this new electrochemical sensor exhibited an excellent electrocatalytic activity to oxidation of peroxynitrite. The mechanism of catalysis was discussed. Based on electrocatalytic oxidation of peroxynitrite at the poly(cyanocobalamin) modified electrode, peroxynitrite was sensitively detected by differential pulse voltammetry. Under optimum conditions, the anodic peak current was linear to concentration of peroxynitrite in the range of 2.0 × 10−6 to 3.0 × 10−4 mol L−1 with a detection limit of 1.0 × 10−7 mol L−1 (S/N of 3). The proposed method has been applied to determination of peroxynitrite in human serum with satisfactory results. This poly(cyanocobalamin) modified electrode showed high selectivity and sensitivity to peroxynitrite determination, which could be used in quantitative detection of peroxynitrite in vivo and in vitro. 相似文献
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Yu Zhang Ruo Yuan Yaqin Chai Xia Zhong Huaan Zhong 《Surface and interface analysis : SIA》2012,44(9):1233-1237
A sensitive nitrite (NO2‐) biosensor was fabricated by using sodium dodecyl sulfate (SDS), Au nanorods, and thionine functionalized MWCNTs (TH‐f‐MWCNTs) nanohybrids modified glassy carbon electrode. TH was covalently immobilized on the MWCNTs via a carbodiimide reaction. Comparing with MWCNTs/GCE, TH‐f‐MWCNTs/GCE displays higher catalytic activity toward the oxidation of NO2‐, since TH not only promoted the electronic transmission but also could improve the concentration of NO2‐ at the surface of the modified electrode in acidic solutions. The Au nanorods (AuNRs) were prepared through a simple wet chemical method and were characterized by TEM. The extremely high surface‐to‐volume ratios associated with one dimension nanostructures make their electrical properties extremely sensitive to species adsorbed on surfaces and result in excellent sensitivity and selectivity. SDS displays excellent film forming ability, which made the electrode stable. Under optimal conditions, the linear range for the detection of nitrite was 0.26 to 51 μM, and the low detection limit was 20 nM. In addition, the modified electrode was successfully applied to determine nitrite in real water samples. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献